Skip to main content

SQL Server 2016 Temporal Tables

SQL Server 2016 introduces a new feature ‘Temporal Tables’. Temporal tables, also named system-versioned tables, allow SQL Server to automatically keep history of the data in the table. Before you typically had to maintain this yourself using triggers or other solutions to keep older versions of your data round.

Note that temporal tables are not a replacement for the change data capture (CDC) feature. CDC uses the transaction log to find the changes and typically those changes are kept for a short period of time (depending on your ETL timeframe). Temporal tables store the actual changes in the history table and they are intended to stay there for a much longer time.

When you want to create a new temporal table, a couple of prerequisites must be met:

  • A primary key must be defined
  • Two columns must be defined to record the start and end date with a data type of datetime2. If needed, these columns can be hidden using the HIDDEN flag. These columns are called the SYSTEM_TIME period columns.
  • INSTEAD OF triggers are not allowed. AFTER triggers are only allowed on the current table.
  • In-memory OLTP cannot be used

A table_history table will be automatically generated when you create a system-versioned table. You can also convert an existing history table to a temporal table.

Great feature! Smile

Temporal-HowWorks

More information here: https://msdn.microsoft.com/en-us/library/dn935015.aspx

Labels:

Popular posts from this blog

Azure DevOps/ GitHub emoji

I’m really bad at remembering emoji’s. So here is cheat sheet with all emoji’s that can be used in tools that support the github emoji markdown markup: All credits go to rcaviers who created this list.
Read more

Kubernetes–Limit your environmental impact

Reducing the carbon footprint and CO2 emission of our (cloud) workloads, is a responsibility of all of us. If you are running a Kubernetes cluster, have a look at Kube-Green . kube-green is a simple Kubernetes operator that automatically shuts down (some of) your pods when you don't need them. A single pod produces about 11 Kg CO2eq per year( here the calculation). Reason enough to give it a try! Installing kube-green in your cluster The easiest way to install the operator in your cluster is through kubectl. We first need to install a cert-manager: kubectl apply -f https://github.com/cert-manager/cert-manager/releases/download/v1.14.5/cert-manager.yaml Remark: Wait a minute before you continue as it can take some time before the cert-manager is up & running inside your cluster. Now we can install the kube-green operator: kubectl apply -f https://github.com/kube-green/kube-green/releases/latest/download/kube-green.yaml Now in the namespace where we want t
Read more

DevToys–A swiss army knife for developers

As a developer there are a lot of small tasks you need to do as part of your coding, debugging and testing activities.  DevToys is an offline windows app that tries to help you with these tasks. Instead of using different websites you get a fully offline experience offering help for a large list of tasks. Many tools are available. Here is the current list: Converters JSON <> YAML Timestamp Number Base Cron Parser Encoders / Decoders HTML URL Base64 Text & Image GZip JWT Decoder Formatters JSON SQL XML Generators Hash (MD5, SHA1, SHA256, SHA512) UUID 1 and 4 Lorem Ipsum Checksum Text Escape / Unescape Inspector & Case Converter Regex Tester Text Comparer XML Validator Markdown Preview Graphic Color B
Read more